I live in a very hot climate and my foliage looked horrible. I was ready to cry. I started studying it. Some would be leaf streak, some would be aphids and some would be leaf miners. I had one garden foliage looked ok. I started noticing I got leaf streak on the aphid daylilies. Literally I prayed what to do. Aphids overhead watering to knock them off, leaf streak no overhead watering, what a contradiction. One spring I took baking soda and dish soap and started my daylily washing program. Many years ago I found out that if you have crazy things occurring in your lawn and garden sprinkling baking soda can cure. I used to use baking soda in my swimming pool. It is a great neutralizer. I also have sandy soil. I wash daylilies early in spring. My foliage has looked better longer. Yes I still get leaf streak but it occurs way less. The bed that never had problems got aphids this year. I was late on my spring washing. Those daylilies had some leaf streak for the first time. In my experience you do not notice something was on your daylilies till the heat hits and the foliage can not handle it. The joy in life is when you care for something. It is even hard to see plants struggle. May you be guided to the best answers!